September 27, 2022

40% of Most Important Colorado Elk Habitat Is Affected by Trail Use

Analysis shows the extent to which recreational trails overlap with important elk habitat in Colorado

Colorado’s resident population and visitor numbers continue to rise, and our year-round presence on recreational trails is impacting elk and other wildlife like never before. When elk are stressed by things like human disturbance, insufficient nutrition, and smaller habitat areas, local populations can struggle and decline.

In Colorado, certain big game herds–including some elk herds—are shrinking, which translates to fewer opportunities for hunters. For the 2022 hunting season, Colorado Parks and Wildlife will issue 1,400 fewer pronghorn licenses, 500 fewer deer licenses, and 800 fewer limited elk tags compared to the 2021 season. The good news is that activities within elk and other big game habitat can be planned and managed to limit impacts when and where it’s needed.

An analysis by the Theodore Roosevelt Conservation Partnership shows that around 40 percent of the most important elk habitat in Colorado is already impacted by non-motorized and motorized trail users. In this analysis we look at the overlap between existing recreational trails and high-priority elk habitat.

We undertook this analysis because trail locations and trail use are factors that are known to change elk behavior and their distribution across the landscape, and as passionate elk hunters and active trail users we wanted to better understand our collective trail-based impacts on Colorado’s elk. This statewide analysis provides land managers and partners with an opportunity to visualize where there is already significant overlap between important elk habitats and mapped trail systems, consider where updated management may help prevent changes in elk distribution and declines in local populations, and decide where it may be wise to avoid or limit future trails.

Figure 1: Map of combined elk winter concentration areas, severe winter range, migration corridors, production areas, and summer concentration areas (light purple area), and the nonmotorized and motorized recreational trail avoidance areas that overlap those habitats (dark purple area).


In Colorado, hunting, fishing, and wildlife watching generate $5 billion in economic activity each year, support 40,000 jobs across the state, and enhance our quality of life, but it’s not just hunters who love wildlife. Outdoor recreationists of all kinds value protecting important wildlife habitats and having opportunities to view wildlife, so the need to maintain, conserve, and protect big game habitats and herds is important to the public at-large. When Colorado residents were surveyed in 2014 and 2019, “opportunities to view wildlife” consistently ranked second in the public’s recreation priorities, behind the desire to have local walking trails/paths. Over that time period, the number of days spent using recreational trails had grown 44 percent, while days spent viewing wildlife had increased by 105 percent.

If we want to have it all—strong, diversified recreation economies; enjoyable, sustainable trail systems; and healthy wildlife populations—public land managers will need to minimize impacts to elk and other big game animals by planning trails to avoid high-priority habitat, restricting activity during the times of year when elk are present, and reducing or limiting the trail density within important elk habitats, if time-of-use restrictions aren’t practical.

A Conservation Success Story Under Threat

Colorado has the largest elk herd in the world, and people love seeing, learning about, photographing, and harvesting them. State agencies, federal land managers, and partners worked hard to bring this population up from its low of only 40,000 elk in Colorado in the early 1900s, to around 300,000 today, but some local populations of elk in Colorado are declining once again.

Decades of wildlife research has documented the impacts of road and trail systems and associated human activities on elk behavior and habitat use. Throughout the year, elk need resting areas, food, water, and the ability to move freely between seasonal habitats to access high-quality forage and other essential resources. Within their overall range, elk migrate to different kinds of habitat throughout the year. Elk generally spend winters at lower elevations, where there’s less snow, then move higher into the mountains in the spring and summer in search of cooler temperatures.

Elk also pass down the knowledge of migration patterns to their offspring. In this way, many seasonal habitats, migration routes, and stopover areas are multigenerational—some are even thousands of years old. When new trails bisect well-established migration routes, or if trails in elk seasonal habitat become busy all year round, it can inhibit elk use of these habitats and negatively affect the herds’ ability to successfully raise offspring, which can over time lead to a declining local population.

Elk can survive in some of our state’s harshest environments, but the research shows that additional disturbance from humans during their toughest times of the year can prove fatal. In a study of the elk herd in Vail, Colorado, researchers found that if cow elk had to move in response to hikers an average of seven times during calving, about 30 percent of their calves died. Resulting data models suggest that if mother elk were disturbed 10 times during calving, all of their calves would die. When researchers stopped sending hikers through calving areas, the calf survival rate recovered. This suggests that limiting disturbance in production areas and summer concentration areas during calving season could help increase elk calf survival rates.

Our Analysis

We used a 2018 study on elk response to trail-based recreation that documented elk avoidance of areas around trails and at what distances, depending on the type of use.

Elk stayed about 547 meters away from hikers; 662 meters away from mountain bike riders; and 879 meters away from ATV riders. Using these avoidance distances, we estimated how much of the highest priority elk habitat on either side of existing trails may be rendered unusable for elk as a consequence of high-frequency trail use. While elk overall range covers a majority of the state, the habitats we used in this analysis cover about one-third of the state and include winter concentration areas, severe winter range, migration corridors, production areas, and summer concentration areas. Because these habitats are particularly important to the elk life cycle and overall population stability, we refer to them in this analysis as high- or highest-priority habitats.

The lower-range estimates for overlap between trail avoidance areas and elk habitats use the hiker avoidance distance along non-motorized trails (547m) and the ATV avoidance distance (879m) along motorized trails.

The higher-range estimates for overlap between trail avoidance areas and elk habitats use the mountain biker avoidance distance (662m) along non-motorized trails and the ATV-avoidance distance (879m) along motorized trails.

The Path Forward

As is, nearly 40 percent of the highest-priority elk habitat in Colorado is at risk of being effectively abandoned by elk due to recreational trails and trail use. It’s imperative that Colorado residents, tourists, and land managers recognize that all land uses can negatively impact the elk and wildlife habitats that are so highly valued by us all. This is why the TRCP is calling for hunters, outdoor recreationists, and local, state, and federal agencies to commit to smart recreation planning and maintaining and conserving functional, intact elk habitats—while we still have them.

Land managers at all levels must be intentional when planning new recreational trails, avoiding the highest-priority habitats altogether or minimizing anticipated impacts by planning for enforceable seasonal closures and lower route density. The recommended management actions described in Colorado Parks and Wildlife’s 2021 Guide to Planning Trails with Wildlife in Mind are meant to avoid and minimize impacts to big game from new trails (Appendix A, pp 44-45) and are consistent with CPW’s recently updated and well-vetted recommendations for its defined high-priority habitats. As other states across the country experience increases in recreation development, this information may serve as a helpful resource in efforts to plan more wisely.

These recommendations specify a density limit of one linear mile per square mile route for motorized and non-motorized roads and trails in migration corridors and other high-priority big game habitats. This helps ensure that important big game habitats are easy for animals to pass through—or “permeable”—and that they remain connected and usable. Conserving different parts of important elk habitat through strategic, science-based management, as well as public education, can increase population stability and resiliency by enabling elk to find the kind of forage, water, and cover they need throughout their lifecycle.

Local, state, and federal agencies are increasingly utilizing the latest data and science on big game animals to guide their recreation development and management decisions, and it’s an important time to make sure more stakeholders are aware of opportunities for better planning and management.

The Colorado Bureau of Land Management intends to incorporate the latest science into Resource Management Plans across the state to maintain, conserve, and protect big game habitat. We encourage the BLM to utilize this science to support responsible recreation planning and management so that Coloradoans can have it all: strong recreation economies, world-class big game populations, and exceptional outdoor recreation opportunities.

Take action using our simple advocacy tool to send this message to the BLM: Colorado BLM can be a leader in responsible recreation management and conservation of big game habitats through the Big Game Corridors RMPA.



Photo by Jasper Nance via Flickr

2 Responses to “40% of Most Important Colorado Elk Habitat Is Affected by Trail Use”

  1. Janet George

    Great analysis and thank you for standing up for our native elk and the habitat for many other wildlife species. What is even more concerning is that there are just as many illegally constructed trails in Colorado as there are authorized system trails so your estimate of elk range impacted is a minimum estimate. Most illegally constructed trails are not mapped other than on certain mobile phone apps like Strava, Alltrails, etc. Public land managers must take action to manage illegal trail construction as well as authorized trail systems if our wildlife habitats and the species it supports are to remain viable.

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September 22, 2022

Unlocking the Winter Range’s Full Potential

Idaho stakeholders come together to take down dated fences 

Impregnable for everything larger than a cottontail, the woven wire fence has stood for decades along Grassy Ridge Road on the Sand Creek winter range in eastern Idaho.

Windblown sand buries the bottom strand in spots, making the structure even more rigid than it was when first installed. Three feet up, parallel strands of barbed wire stretch above a wire netting barrier, making it impossible for a grown man to straddle. The combined effect is perfect for keeping all manner of livestock, from sheep to cattle, off the adjacent county road and on the private property or public land grazing allotments where they belong.

But it also makes life more difficult for the area’s wildlife. Pronghorn antelope no longer migrate to this corner of the desert. Elk still move in and out, as do mule deer, which flock to the area around the Grassy Ridge Road by the thousands. But even for these larger ungulates, the fence has its consequences. The carcass of a deer, leg tangled in wire from a poorly calculated jump, is a common sight for travelers along the road.

“It is pretty tough for animals to cross this,” said Gerren Steel, Idaho Department of Fish and Game volunteer coordinator.

The Grassy Ridge Road fence, like miles and miles of similar structures across the West, was built at a time when its effects on wildlife movement were not well understood, let alone considered. Today, however, priorities have shifted, and the fence is getting a facelift. It is being retrofitted with a wildlife-friendly design by a group of unlikely allies working to save the Sand Creek winter range from a variety of threats.

Roughly 8,500 deer, elk, moose, and pronghorns spend the winter on the Sand Creek desert, which sits between the towns of St. Anthony and Dubois in eastern Idaho’s Fremont and Clark counties. The winter range is a 500,000-acre patchwork of Bureau of Land Management public lands, state endowment lands managed by the Idaho Department of Lands, deeded Idaho Fish and Game Lands, and private property.

Sand Creek is one of the last best bastions of sagebrush steppe in eastern Idaho, lush with sagebrush, bitterbrush, chokecherry, junipers, and rabbitbrush. Its quality, however, is being diminished slowly and surely. On the eastern boundary, human development encroaches in the form of platted subdivisions. To the west, the 2018 Grassy Ridge wildfire burnt a quarter of the winter range, robbing animals of forage and cover. And across the desert, motorized recreationists carelessly punch illegal routes across the sage, further fragmenting the habitat that is the foundation of this famed winter range.

There is hope, however, for this landscape and the big game herds that depend on it. State and federal agencies—including the BLM, IDFG, IDL, Natural Resource Conservation Service, and U.S. Fish and Wildlife Service—along with conservationists, sportsmen and sportswomen, and private landowners are working together to sustainably manage this important habitat. Over the past three years, the Sand Creek collaborative has worked collectively to design and build firebreaks to protect the remaining healthy winter range from the threat of outsized wildfires brought on by climate change. The group has also designed and implemented vegetation treatments to promote livestock forage and diversify the age structure of sagebrush stands. The goals of their collaboration are preventing large wildfires, improving wildlife habitat, and providing for a working landscape.


Today, the group’s conservation work comes in the form of fixing a fence in the heart of the winter range.

Steel, from Fish and Game, and habitat biologist Tim Swearingen leapfrog each other along the fence line, separating the barbed wire and net wire fence from the posts that hold it tight. It is slow work as they cut the fencing away from the posts and lay it on the ground. Afterwards, a USFWS partner biologist utilizes a skid steer equipped with a mounted fence roller to collect the downed fence.

The posts will remain where they are, and a new wildlife-friendly fence will replace the old barbed and woven wire. A new bottom wire—smooth, not barbed—will be 16 inches off the ground. The wider gap between the fence bottom and the ground will keep livestock where they should be, while providing the opportunity for pronghorns, mule deer fawns, and elk calves to slide underneath, hopefully unharmed. On the other end, the top wire of the fence will be 42 inches off the ground, again still tall enough to contain livestock while making it easier for deer and elk to jump the barrier.

Swearingen hopes to take down and replace four miles of fence this fall. IDFG will provide the labor, using a cadre of volunteers. USFWS will contribute fence removal expertise and contracting oversight, and the NRCS is footing the bill for the materials. There is no cost to private landowners and public land grazers, but the benefits to all will be obvious.

Hundreds of miles of fence still remain, but Swearingen is happy with the day’s progress.

“We are making the range more wildlife-friendly, slowly and surely,” he said.

Get to Know a Key Everglades Restoration Project that Will Improve Wetlands and Estuaries

What is the Everglades Agricultural Area Reservoir and why is it important to hunters and anglers?

The iconic Everglades ecosystem contains some of America’s largest estuaries and life-giving wetlands, which provide essential habitat to sportfish and game species. One key project will help to restore and conserve these important elements of America’s Everglades: the Everglades Agricultural Area Reservoir.

The EAA Reservoir has two primary features—a treatment wetland that will clean the water from Lake Okeechobee and a reservoir that will store excess water from the lake. The wetland will be built by the state-run South Florida Water Management District, and the reservoir will be built by the U.S. Army Corps of Engineers.

This project is necessary to restore the natural north-to-south water flows that once sustained the ecosystem. Before the watershed was reshaped by development in the last century, water flows created a “river of grass” throughout south Florida that extended to both the east and west coasts. Most of the historic Everglades now lays dry, as farmland and housing developments have taken the place of functional wetlands.

These days, water is transported from Lake Okeechobee to the coasts and southern Everglades through a complex system of pumps, levees, and canals. This water is rich in phosphorus from fertilizer and manure runoff, which leads to massive algae blooms.

The EAA reservoir will help filter and send cleaner freshwater south to drain into the Florida Bay and Gulf of Mexico. In these areas, freshwater and seawater mix to create brackish water estuaries, which are breeding grounds and nurseries for many of the fish, crustaceans, and shellfish that anglers love to pursue. Cleaner water and healthier sea grasses will benefit populations of spotted seatrout, redfish, tarpon, largemouth bass, and peacock bass when the reservoir is complete.

Historically, the Everglades has also provided essential habitat for waterfowl, deer, turkeys and other game species. But poorer habitat conditions and recent harmful algae blooms have killed off much of the food that game and waterfowl rely on. The EAA reservoir will be a boon for these species as new wetlands become loaded with aquatic vegetation that filters out nutrients before the water flows south.

The TRCP is pushing Congress to allocate the funding necessary to complete this project and restore and conserve America’s Everglades. Take action using our simple advocacy tool to tell your lawmakers you support full funding and expedient completion of Everglades restoration work.

September 21, 2022

Changes Coming Soon for Atlantic Menhaden Harvesters

Fisheries managers are meeting in November to debate and adopt changes to the Atlantic menhaden interstate fishery management plan—anglers have weighed in, but many of our concerns won’t be addressed

In November, the Menhaden Management Board of the Atlantic States Marine Fisheries Commission will consider public comments submitted since August about proposed changes to the Atlantic Menhaden Interstate Fishery Management Plan. The draft addendum up for vote deals with reallocation of each Atlantic Coast state’s yearly menhaden commercial fishing quota and changes to various programs that give states opportunities to harvest additional quota throughout the season.

The plan and options proposed in this addendum are extremely granular—the average angler does not need to wade through and understand it all. What you do need to know is that the TRCP and our sportfishing partners have weighed in with the ASMFC on our preferred options, which we believe would best benefit recreational fishing, sportfish, and the overall health of our marine food web.

It is also important for anglers to understand how industrial reduction fishing fits into this reallocation math. Remember: Virginia is the only Atlantic state that still allows menhaden reduction fishing in its waters, and a single foreign-owned company—Omega Protein, operating out of Virginia—does all of the reduction fishing for menhaden on the Atlantic Coast. Most of the other harvesters who take menhaden out of the water, based on the state allocations up for vote, are fishing for bait that is then sold to anglers. This activity supports many small businesses in parts of the Northeast.

But many states, most notably Maine, have had to reckon with the mismatch of state allocations versus actual availability of menhaden in their state waters, forcing them to depend on conditional programs and quota transfers from other states just to maintain their bait fishing fleets. Virginia, meanwhile, holds much of the power within the fishery, even after years of debate about equity among states participating in the plan.

The numbers make this very clear: Virginia is allotted more than 78 percent of the coastwide quota now and, at worst, they will end up with 73.6 percent of the coastwide quota after the Menhaden Management Board chooses from the available options this fall. Does that sound fair for a fishery with 16 states participating?

The TRCP and our partners have been following this addendum planning process for the past year, and we’re supporting the options that most accurately reflect the current needs of the fishery and the availability of the menhaden resource along the coast, in order to lower states’ reliance on one-time programs and quota transfers that keep them limping from season to season. We’re also pushing for each menhaden taken out of the water to be counted toward the coastwide quota, a universally embraced best practice for sound fisheries management that (unbelievably) isn’t required in the menhaden fishery right now.

Our coalition has also expressed concerns about what’s not included in the proposed plan update.

This includes consideration of where commercial harvest should happen within the menhaden’s range. While the recent single-species stock assessment found the Atlantic menhaden stock to be above the biomass target, how that biomass is distributed and fished along the coast will impact predator stocks, including recovering populations of striped bass and bluefish that depend on the availability of various year classes of menhaden and other forage species throughout their range.

We believe that the fishery should be distributed throughout the menhaden’s known geographic range, not concentrated nearshore in sensitive nursery habitats at the center of their range, as it is now. With the fisheries’ effort and catch centered at the menhaden population’s natal area and focused on juveniles (ages 0-2), this prevents larger, more fecund individuals from existing in the stock.

Further, the fishery should not be dominated by industrial fisheries, but rather enable the growth of smaller-scale and local commercial and recreational fisheries.

Finally, we are concerned that the setting of the coastwide total allowable catch for the 2023 season may disregard vital ecosystem effects, because the latest menhaden stock assessment update did not use updated data on certain species which would impact menhaden availability in the water.

For example, the 2022 Atlantic Herring Management Track Assessment concluded that herring remain overfished at just 21 percent of their target biomass. The 2021-2022 total allowable catch of 194,400 metric tons of menhaden was set using species data from 2017, prior to the decline of the Atlantic herring stock. Herring is a primary alternative prey species to menhaden, so this depletion has likely had wide-ranging effects on both prey and predators since 2017, and these impacts will continue as the resource slowly rebuilds.

Menhaden are increasingly important as bait to compensate for shortages of not only Atlantic herring but also river herring and mackerel, and they, of course, remain important as a food source for predators as well. This is why we’ll continue to push for a precautionary approach to quota-setting for the 2023 season, updated ecosystem data in the next stock assessment, and consideration of the current total allowable catch as a maximum value, not as a baseline.

There are a few limited opportunities for informed anglers to engage in the draft addendum debate before the end of September—if you’re interested in attending a public hearing to speak up for menhaden and sportfish, please email Jaclyn Higgins for more information.


Photo by Gaelin Rosenwaks. Follow her on Instagram @gaelingoexplore.

September 15, 2022

Majority of Americans Support the Recovering America’s Wildlife Act

70 percent of survey respondents back proposed legislation that would create new source of conservation funding

A new survey conducted by Responsive Management finds that 70 percent of Americans support the Recovering America’s Wildlife Act, pending federal legislation that would allocate an additional $1.4 billion in annual funding to state agencies and Tribal land managers for wildlife conservation.

State-level wildlife conservation efforts in the United States have historically been funded largely by hunters and recreational shooters through an excise tax on their purchases of firearms, pistols, and ammunition. This funding mechanism was created in 1937 through the Federal Aid in Wildlife Restoration Act (often referred to as the “Pittman-Robertson Act” for the legislators who sponsored it.) Because Pittman-Robertson funding comes mostly from sportsmen and sportswomen, it has generally been used by state fish and wildlife agencies to manage game species. For instance, Pittman-Robertson excise tax revenues have helped to fund the recovery of whitetail deer, Rocky Mountain elk, wild turkeys, and many other iconic North American game animals.

While the Pittman-Robertson system has been a major success for almost a century, more than 12,000 wildlife species—including threatened and endangered species and other animals—remain in need of conservation and restoration. The Recovering America’s Wildlife Act is designed to address these needs and strengthen the current wildlife conservation funding model by redirecting $1.4 billion to state fish and wildlife agencies and Tribal wildlife managers for the conservation and restoration of wildlife and plant species of greatest conservation need.

In a time of stark political polarization, RAWA appears to be one of the few causes able to unite both Democrats and Republicans: The bill passed the U.S. House of Representatives with bipartisan support in June and has been introduced in the U.S. Senate, where it is expected to be voted on this month.

The survey conducted by Responsive Management marks one of the first major assessments of public opinion on RAWA. In the survey, respondents were first read a description of the legislation that explained the purpose of the bill and the funding source. They were then asked whether they supported or opposed the Recovering America’s Wildlife Act. A total of 70 percent of adult U.S. residents expressed support for RAWA, including 42 percent who indicated strong support, compared to only 5 percent who oppose the measure.

Reflecting the bipartisan support for the bill in the House, the survey found strong support for RAWA across the political spectrum, with majorities of Democrats (82 percent), Republicans (64 percent), and independents (64 percent) supporting the legislation.

Furthermore, the survey identified majority support for RAWA among every major demographic group examined in the research, including males and females; younger, middle-aged, and older residents; those of higher and lower education levels; and those in urban, suburban, and rural areas. RAWA was also supported by diverse outdoor recreationists, including 80 percent of wildlife viewers, 78 percent of anglers, 77 percent of birdwatchers, and 70 percent of hunters.

“I was initially surprised at how high the support for RAWA was in the survey,” said Responsive Management Executive Director Mark Damian Duda. “But the truth is that, over three decades of survey research, we’ve seen that Americans consistently back conservation issues. In fact, in the last several elections, upwards of 75 percent of the ballot measures on wildlife, habitat, and green issues around the country pass. When these issues are presented directly to the people, Americans tend to vote consistently in favor of conservation.”

“Something we understand well as wildlife managers and representatives of state agencies is that wildlife conservation transcends party politics, and this polling demonstrates that,” said Ron Regan, Executive Director of the Association of Fish & Wildlife Agencies. “The Recovering America’s Wildlife Act is the single most impactful wildlife conservation bill in a generation.”

The scientific, probability-based survey was conducted August 25 to 28, 2022, and used a random sample of 1,002 United States residents ages 18 and older. The survey was fielded through a combination of telephone (including landline and cellular numbers) and online interviews. (The use of supplemental online interviews allowed for greater representation of younger residents, as research indicates that younger people are less likely to complete a telephone survey than they are to complete a survey online.) For the entire sample of adult U.S. residents, the sampling error is at most plus or minus 3.1 percentage points.

Learn more at responsivemanagement.com.



Theodore Roosevelt’s experiences hunting and fishing certainly fueled his passion for conservation, but it seems that a passion for coffee may have powered his mornings. In fact, Roosevelt’s son once said that his father’s coffee cup was “more in the nature of a bathtub.” TRCP has partnered with Afuera Coffee Co. to bring together his two loves: a strong morning brew and a dedication to conservation. With your purchase, you’ll not only enjoy waking up to the rich aroma of this bolder roast—you’ll be supporting the important work of preserving hunting and fishing opportunities for all.

$4 from each bag is donated to the TRCP, to help continue their efforts of safeguarding critical habitats, productive hunting grounds, and favorite fishing holes for future generations.

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